Windows Prefetch is a critical forensic artifact that helps track program execution history. While Prefetch files can be manually analyzed, forensic tools like PECmd (by Eric Zimmerman) and WinPrefetchView (by NirSoft) simplify and enhance the analysis process.
We will cover:
✅ How PECmd extracts and formats Prefetch data
✅ How to analyze Prefetch files using WinPrefetchView
✅ Best practices for interpreting Prefetch execution timestamps
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Using PECmd to Analyze Prefetch Files
PECmd is a powerful command-line tool for parsing Prefetch files, extracting valuable metadata, and generating structured reports.
1️⃣ Analyzing a Single Prefetch File (-f option)
To extract detailed metadata from a single .pf file, run:
PECmd.exe -f C:\Windows\Prefetch\example.exe-12345678.pf
This outputs:
Executable Name & Path
Prefetch Hash & File Size
Prefetch Version
Run Count (how many times the application was executed)
Last Execution Timestamp(s)
Windows 7 and earlier: 1 timestamp
Windows 8+: Up to 8 execution timestamps
💡 Timestamp Validation:
The last run time should match the last modified timestamp of the .pf file.
Subtract ~10 seconds for accuracy when using file system timestamps.
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2️⃣ Batch Processing: Parsing an Entire Prefetch Folder (-d option)
To process all Prefetch files in a directory:
PECmd.exe -d G:\G\Windows\prefetch --csv "E:\Output for testing" --csvf Prefetch.csv
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This generates two output files:1️⃣ CSV Report:
Contains execution details for all parsed Prefetch files.
Useful for filtering by run count or searching for specific applications.
2️⃣ Timeline View:
Extracts all embedded execution timestamps from Prefetch files.
Provides a chronological list of program executions, helping correlate events.
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Using WinPrefetchView for GUI-Based Analysis
WinPrefetchView (by NirSoft) provides a graphical interface for analyzing Prefetch data.
How to Use WinPrefetchView
1️⃣ Open WinPrefetchView
2️⃣ Go to Options > Advanced Options
3️⃣ Select Prefetch Folder (C:\Windows\Prefetch\ or a forensic image)
4️⃣ Click OK to parse Prefetch files
📌 Key Features:
✅ Displays Run Count, Last Run Time, and File References
✅ Extracts up to 8 execution timestamps
✅ Lists files accessed by the application within the first 10 seconds
🚀 Takeaway: Prefetch file references can reveal hidden malware, deleted tools, or important user actions that might otherwise go undetected.
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Best Practices for Prefetch Analysis
🔍 1. Prioritize Prefetch Collection
Running forensic tools on a live system creates new Prefetch files, potentially overwriting older evidence.
Collect Prefetch files before executing forensic tools.
🔍 2. Cross-Reference Prefetch Data
Combine Prefetch analysis with:
UserAssist (tracks GUI-based program executions)
AmCache (records detailed program metadata)
BAM/DAM (tracks recent executions)
🔍 3. Look for Anomalous Prefetch Files
Multiple Prefetch files for the same executable but with different hashes may indicate:
Malware running from multiple locations
Renamed executables attempting to evade detection
🔍 4. Ensure Timestamps Are Interpreted Correctly
Convert Windows FILETIME timestamps properly.
Keep your forensic VM in UTC time to prevent automatic time conversions by analysis tools.
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Final Thoughts: Mastering Prefetch Analysis with PECmd & WinPrefetchView
PECmd and WinPrefetchView are essential tools for extracting, organizing, and analyzing Windows Prefetch data.
💡 Key Takeaways:
✅ PECmd is ideal for batch processing and timeline analysis.
✅ WinPrefetchView provides a user-friendly interface for reviewing Prefetch files.
✅ Prefetch timestamps help reconstruct program execution history—even for deleted applications.
✅ File references inside Prefetch files can reveal hidden malware or deleted forensic evidence.
🚀 If you're investigating program execution on a Windows system, Prefetch analysis should be one of your first steps! 🔍
-----------------------------------------Dean-----------------------------------------------
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